code: def test_zone_parameter(self):
      aug = nas.LoudnessAug(zone=(0, 1))
      aug = nas.LoudnessAug(zone=(0.5, 0.7))
      aug = nas.LoudnessAug(zone=(0.6, 1))
  
      with self.assertRaises(ValueError) as context:
          aug = nas.LoudnessAug(zone=(-1, 1))
      self.assertTrue(
          "Lower bound of zone is smaller than"
          in str(context.exception)
      )
  
      with self.assertRaises(ValueError) as context:
          aug = nas.LoudnessAug(zone=(0, 1.2))
      self.assertTrue(
          "Upper bound of zone is larger than" in str(context.exception)
      )
  
file_path: nlpaug/test/augmenter/spectrogram/test_spectrogram.py
imports: import unittest
  import os
  from dotenv import load_dotenv
  from nlpaug.util import AudioLoader
  import nlpaug.augmenter.spectrogram
label_desc: Use image node_id 3 for calling the TestFrequencyMasking obj's underlying member method code with example usage: obj.test_zone_parameter() without return types